The plot is called the marginal cost of capital (MCC) schedule because it shows the cost of each
additional, or marginal, dollar raised (the marginal cost).
l(1). The IOS schedule is a plot of the projects being considered by cost and in descending order of IRR.
Note that Coleman actually faces two IOS schedules—one with Projects A, B, and C, and another with
Projects A, B*, and C.
IOS
($ Thousands)
10.0
15.0
MCC
A firm’s marginal cost of capital is defined by the intersection of the IOS and MCC schedules.
Therefore, Coleman’s MCC is 12.7 percent.
l(2). If a project has average risk, then its cost of capital is the firm’s MCC. Thus, assuming average risk, all
projects should be discounted at the firm’s 12.7 percent MCC. Because the IRR and NPV rules lead to
the same accept/reject decisions for independent projects, all independent projects with IRRs above
12.7 percent should be accepted. Thus, Project A is acceptable but Project C is not.
l(3). As more and more new capital is required in any year, Coleman’s WACC would eventually begin to
rise above 12.7 percent. The company would have to find new buyers for its debt, preferred, and
common stock, and those new buyers would require higher rates of return to be enticed to invest in